Loose Bead Insulation query

[Tommohwak]

Getting older and colder, and trying to do whatever I sensibly can to insulate our property! (1980's three bed bungalow with gas CH) The loft has about 300mm rockwool, walls have some kind of blown in lightweight insulation, so only really the floor to play with.

 

Construction seems to be concrete with screed, membrane, 50mm battens supporting 18mm T and G chipboard. There is a garage under part of the house, and I'm guessing thats concrete beam and block, and screed with batten and T and G same as the rest. Quite decent looking underlay and carpet throughout (apart from bathroom kitchen)

 

I removed a section of board in the hall, and it looks OK, no sign of damp although that section has the CH pipes running through it - no reason to suspect any issues. So I think I have a few options.

 

1. Rip up al the board and skirting, and fill between battens with Celotex or similar. Not easy, because the batten placement isn't very regular, and a certain amount of upheaval to which my wife has an allergy.

2. Rip up boards and skirt + battens  and do Celotex or similar floating floor. Screed isnt even, so would need re-screeding which would reduce depth a bit. 

3. Drill eg 20mm holes through T and G and fill with beads - maybe blow into void with some kind of blower. Not sure how easily the beads would flow and how complete the void would fill. 50mm beads would get me R of 1.56 approx, vs 0.4 approx for 50mm air, vs 2.2 for 50mm celotex (or vs 4.0 I think for latest reg. Hopefully those numbers look about right?

5. Turn up the heating and grease the wallet.

 

I'm thinking about 3 - seems a reasonable compromise between hassle and result. Anyone got any thoughts pls? Thanks in advance!

[Radian]

Tricky one. And welcome. Unfortunately the battens are a cold bridge that will hold you back while they're still there supporting the T&G

It all depends on the percentage of insulation being lost that they represent. Definitely worth doing an analysis of your build-up if you can characterise it sufficiently well to put the details into a calculator like ubakus.com

If you did go for floating PUR floor (and with only 50mm available, rigid foam PUR is the only insulation worth going to all the effort for) you can level the screed with sharp sand which will add the absolute minimum.

[Tommohwak]

Ok Radian thanks for that. Yeah the battens are a bridge which doesn't help.

But tearing up the floor won't be popular which is why I thought beads might get more bang per buck. 

Re calculators, thats difficult because not 100% sure of structure. 

Edited December 9, 2022 by Tommohwak